Lifting-jack



A. B. PROBASCO. Lifting Jack.

No; 232,367. Patented sept.. 21, 1880;

Mm Naht/MNM Www/wurd UNITED STATES PATENT Eric ABRAHAM B. PROBASOO, OF LEBANON, OHIO.

LVIFTING-JACK.

SPECIFICATION forming part of Letters Patent No. 232,367, dated September 21,` 1880.

l v Application filed January 5, 1880. v

To all whom t mag/concern:

Be it known that I, ABRAHAM B. PRoBAsco, of Lebanon, arren county, Ohio, have invented a new and useful Improvement in Lifting-Jacks, of which the following is a specification.

My improvement relates to the class of liftin g-jacks in which pawls depending from a lever operate alternately on ratcheted edges upon opposite sides of the lifting-bar so as to elevate said bar.

A distinguishing feature of my invention im a vibratory tappet whose engagement by the lever at certain portions of its stroke operates to lift and hold each pawl alternately away from the ratchet and permit the descent of the lifting-bar when" so desired. y

The construction and arrangement of the parts are such that a moderate vibration of the lever operates to elevate the lifting-bar, and such that a wider vibration of the lever operates to permit the gradual descent of the lifting-bar through the instrumentality of the' said tappet coacting with the same pawls which have served to lift the bar.

In the accompanying drawings, Figure l is a perspective view of my jack as employed for lifting. Fig. 2 is a side elevation, in which the releasing-tappet is shown in action so as to permit the descent of the lifting-bar. Fig. 3 is a vertical section of the apparatus in its locked condition. Fig. 4 is a section through the pawl-pivots in the locked position of the lever. Fig. 5 shows one of the pawls detached. Fig. 6 is a rear view of the releasing pawl or tappet.

A A represent two similar standards, which rise vertically from a base or foot, B. The portions A A B may constitute a single integral casting, as shown.

My lifting-bar consists of a casting, (l, whose opposite edges have ratchet-teeth 1) D', so located that the teeth of one edge are opposite the intervals of the other edge.. The liftingbar C occupies the space between the standards A A', and is guided longitudinally thereof by a brace-piece, E, which occupies a slot, c, in said bar, and is screwed fast to thc standards by a through-bolt, F, occupying sleeves or thimblcs Gr, which collectively constitute the fulcrum of the operative lever. My preferred construction for this lever is shown iuthe drawings, and comprises a wooden handle,

II, which is firmly secured by flanges fi and bolts J within the cheeks I, which cheeks have oriices at t" to receive the saldthimbles G, and one of which cheeks has spurs z'", for a purpose hereinafter explained.

Proj octing from the inner face of each cheek I are two studs, t", which constitute the points of suspension of two similar pawls, K K'. These pawls are identical in form, save in being made, right and left to suit the two opposite sides of the jack, and consequently the construction-of both may be understood from a description of either one. Fig. 5 represents the left-hand pawl K, or that most remote from the handle.

7c 7o are two cheeks, connected at bottom by a bar, 7c, fitted to engage with the teeth ofthe appropriate rack, and connected at top by a bar, 70', which serves as a counterpoise to cause the bar 7c" to seek and engage with the rack-teeth. Oritices kw receive the studprojections i" from the lever. One cheek, 7c, is prolonged down ward, and terminates in a hook, 7c", for a purpose which will now be explained.

Depending from a stud or pivot, L', on the standard A is a tappet, L, having an upwardly-presented tongue, l, which, when the handle is vibrated beyond a certain point, engages with one or other spur, t, of the lever. Said tappet has also two laterally-projecting tongues, l', of which each has a rearwardlyprojecting spur, Z, of which each spur in turn engages with the corresponding hook la", and remains so engaged until released by the impact of the corresponding spur on the other side of the tappet with the edge of the standard, as hereinafter explained.

In operating my jack for elevating the lifting-bar the handle is vibrated only sufficiently to alternately engage the respective pawls with their appropriate racks, the handle being reversed immediately after the/engagement with the opposite pawl, so as to bring it into active service, and at the same time permit the other pawl to slip down and engage with a new tooth on its rack. If, on the contrary, it be desired to lower the lifting-bar, the handle, instead of being reversed at the above-mentioned juncture, is vibrated onward until one of its IOO spurs i engages the tongue l of the tappet L, so as to cause the hook kv to slide outward over and engage behind and underneath the tongue l nearest to it. rlhis having been acplished, the handle is now reversed, so as to permit the descent of the lifting-bar, the said hook operating in the meantime to hold the said paWl out long enough to permit a rackhook to drop past it unopposed. A farther onward motion of the handle in the new direction repeats this operation on the other side, and so on alternately until the lifting-bar is completely lowered, or snfciently so to permit the object to rest upon the ground and the 15 jack to be withdraw, after which the liftingbar may be dropped the remaining distance, it desired, by grasping' the upper part of each pawl so as to libera te both pawls from the rack. When the lifting-bar has been raised to the desired height it becomes self-locked thereto by leaving' the lever at that position, which causes both pawls to engage with rack-teeth, as shown in Fig. 3.

I claim as new and of my inventionl. The combination, with the standardAA/ B, brace-guide E, and double-ratchet liftingbar C, ot' the lever H I t' t" i 45', the pawls K, cheeks 7c It', bars 7c 76', hook kv, and the double-actin g tappet L Z l l, substantially as described.

2; In a lifting-jack whose lifting-bar is provided with double ratchet, a pair of pawls and operating-lever, the tappet L, pivoted to the upper part of the standard, and having an upwardlypresented tongue, l, laterallyprojecting tongues l 1,', and rearwardly-projecting spurs l l, for coacting with projections kV i t on the pawls and lever, substantially as and for the purpose set forth.

In testimony of which invention I hereunto set my hand.

ABRAHAM B. PROBASCO.

Att-est:

GEO. H. KNIGHT, W. TYsoN J UDKINs. 

